The present invention generally relates to an electrical connector for a power distribution system. More specifically, the invention relates to an electrical connector, such as a bushing insert, having a dual action piston that moves between retracted and extended positions. During fault closure, the dual action piston hastens connection of the electrical connector with another electrical device of the power distribution system, thereby halting the formation of flashover or electrical arc.
Conventional high voltage electrical connectors, such as bushing inserts, connect such devices as transformers to electrical equipment of a power distribution system. Typically, the electrical connector is connected to another electrical device of the power distribution system, such as a cable connector, with female contacts of the electrical connector mating with male contacts of the cable connector.
During a loadmake or connection of the electrical connector and the cable connector, an arc is struck between the contact elements as they approach one another. The arc formed during loadmake is acceptable since the arc is of generally moderate intensity and is quenched as soon as the contact elements are engaged. However, during fault closure, or short circuit conditions, a substantial arc can occur between the contact elements of the connectors resulting in catastrophic failure of the electrical connector including extensive damage and possible explosion.
Conventional electrical connectors employ a piston that moves the female contact of the electrical connector into engagement with the male contact of the cable connector during fault conditions, thereby hastening the engagement of the contacts, which in turn substantially eliminates any arc that has formed therebetween. As a result, however, the conventional electrical connectors must be adapted to accommodate the shape of the movable piston which must be of sufficient length to hasten the connection of the contacts elements and eliminate any arc.
Examples of conventional high voltage electrical connectors are disclosed in U.S. Pat. No. 3,930,709 to Stanger et al.; U.S. Pat. No. 3,982,812 to Boliver; U.S. Pat. No. 4,008,943 to Flatt et al.; U.S. Pat. No. 4,119,358 to Tachick et al.; U.S. Pat. No. 4,186,985 to Stepniak et al.; U.S. Pat. No. 4,773,872 to Borgstrom et al.; and U.S. Pat. No. 5,445,533 to Roscizewski et al.
Accordingly, an object of the present invention is to provide an electrical connector that includes a mechanism for hastening connection of the electrical connector with another electrical device, thereby substantially quenching the formation of any arc therebetween during fault conditions.
Another object of the present invention is to provide an electrical connector that includes a piston assembly for hastening connection of the electrical connector and another electrical device that is adapted to reduce the amount of space required by the electrical connector to accommodate the piston assembly.
Yet another object of the present invention is to provide an electrical connector that includes a piston assembly having telescoping members which move between retracted and extended positions to facilitate hastening the connection of the contact elements of the electrical connectors and reduce the size of the piston assembly.
The foregoing objects are basically attained by an electrical connector, comprising a housing that has an inner bore, a first end and a second end that is opposite the first end. The second end has an opening that provides access to the inner bore. A piston is received within the inner bore of the housing and includes a first sleeve and a second sleeve. The first and second sleeves are coaxial and slidably engaged in a telescoping arrangement, and are movable between a retracted position and an extended position by sliding the first and second sleeves with respect to one another within the inner bore of said housing. A contact element is on the second sleeve and movable therewith between first and second axially spaced positions within the inner bore.
The foregoing objects are also attained by an electrical connector assembly, comprising an electrical connector that includes a housing with an inner bore, a first end, and a second end opposite the first end. The second end has an opening providing access to the inner bore. A piston is received within the inner bore of the housing proximate the first end, and includes first and second sleeves coaxially and slidably engaged in a telescoping arrangement, and a contact element on the second sleeve that is movable therewith. An electrical device has a contact element that engages the contact element of the piston of the electrical connector. The first and second sleeves of the piston move between a retracted position and an extended position upon sliding the first and second sleeves with respect to one another within the inner bore of the housing of the electrical connector due to generation of internal gases upon mating of the electrical connector and the electrical device.
By fashioning the electrical connector in this manner, a dual action piston assembly both reduces the size of the electrical connector and provides an effective mechanism for hastening the connection of the contact elements of the electrical connector and an electrical device during a fault closure.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with annexed drawings, discloses a preferred embodiment of the present invention.